This application claims the priority of German Application 100 07 505.3, filed Feb. 18, 2000, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to an. electric driving system, particularly for press systems and/or their components, comprising a main electric motor (5) for driving a flywheel (2) to drive a drive shaft (4) via a releasable coupling device, and an auxiliary electric motor (12) utilizable for driving the drive shaft.
A known driving system is described in DE 44 21 527 C2. Because of the two electric motors used in this driving system, a relatively variable drive of a press system can be obtained. The driving system described there is, among other things, because of the installation space required by it and because of its cumbersome construction, limited to a very narrow field of application.
An object of the present invention is to provide an electric driving system which can be operated in a very variable manner, can be used at very low expenditures for many different application purposes and requires only little space.
According to the invention, this object has been achieved by arranging the main and auxiliary motors within the flywheel.
As a result of the accommodation of the main electric motor and of the auxiliary electric motor within the flywheel, a modular construction of the electric driving system is obtained which permits the use of the driving system according to the invention for many different purposes. For example, the present invention can be used in many different types of press systems and individual presses and their components, as for example, in the case of ejector systems or transfer systems, and which requires little space.
The construction according to the present invention leads to an extremely compact driving system which, in many different applications, requires very low adaptation and mounting expenditures. As a result of the two mutually independent electric motors in the case of, for example, presses, the no-load stroke can be completely uncoupled from the working stroke, whereby particularly the no-load stroke is freely programmable.
In advantageous further developments of the present invention, a liquid cooling for the main electric motor and/or the auxiliary electric motor can be provided. This liquid cooling, which permits a considerably larger output of the respective liquid-cooled electric motor, can be used because of the compact construction of the driving system according to the invention whereas, with conventional driving systems, considerable difficulties were sometimes caused.